LAUSR

Aluminizing process is an important technology in which aluminum is introduced into the surface of base material. In this work, aluminized layers were produced by the pack cementation process on Inconel 600, Inconel 625 and Nimonic 90 nickel-based alloys. Powder mixture contained 80% of Al and 20% of Fe–Cr. Microstructure, hardness, chemical composition and heat resistance were investigated. The microstructure consisted of intermetallic phases near the surface, and below them, the solid solution was observed. The oxidation resistance at elevated temperature of alloys with the layer was compared with pure alloys. After 20-h annealing at 1000 °C, the phase analysis was carried out. On the Nimonic 90 with aluminized coatings, a lot of Cr2O3 and Al2O3 oxides were produced, whereas on the pure Nimonic 90, a lot of NiO oxides were observed. It was found that the best heat resistance was obtained for the layer produced on the Nimonic 90.